88 Johnson SPL - overheat alarm

Have a 1990 88Johnson SPl that is giving me fits with an overheat alarm. It'll throw the alarm if I leave it idling for 5 mins or so. Water pressure is good, impellar has been changed, complete kit. Now, about a yr ago we pulled the heads and changed the water deflectors and thermostats too. It seemed to run good, then started these issues again. Saw intermittent pressure on the pump so changed it, but even with good pressure, it's giving me an alarm. Pulling the heads was a PITA
Do you think the deflectors could be the issue?
One guy told me a fuel mixture issue from carbs could cause this??Running too lean?

Have you checked the intake screen on lower unit. You may get water out pee hole but not enough flow to cool block. At idle I doubt carbs would be an issue. I would lean towards a electrical problem more than cooling problem. Have you changed sensor or traced out wiring to check for bare spot in a wire grounding out?

Here is something you might want to try. Can get different temp ratings just to check and see if motor is actually getting that hot.
https://www.amazon.com/Markal-Thermo...07234891&psc=1

Or you could buy a cheap thermal heat gun to check temp while running.

Hey Cray, I do have a cheap HF heat gun.. It told me 180's I believe the last time. I didn't have it with me this past weekend to check when the alarm went off idling.
The intakes are clear.. I havent' changed the sensors, I may unplug try some tests and go that route...
Weird thing, it threw overheat before, I said the heck with it as it was raining and needed to get back to camp, couple minutes later it shut off so you may be on to something with the sensors